A modified Johnson-Cook constitutive model for improved thermal softening prediction of machining simulations in C45 steel

Priest, J., Ghadbeigi, H., Ayvar-Soberanis, S. orcid.org/0000-0002-1899-9743 et al. (2 more authors) (2022) A modified Johnson-Cook constitutive model for improved thermal softening prediction of machining simulations in C45 steel. In: Rech, J. and Outeiro, J., (eds.) Procedia CIRP. 6th CIRP Conference on Surface Integrity, 08-10 Jun 2022, Lyon, France. Elsevier BV , pp. 106-111.

Abstract

A new modified Johnson-Cook model is developed to capture the non-linear thermal softening behaviour below the austenite transformation temperature (723°C) in C45 ferritic-pearlitic steel, which is not captured by the original Johnson-Cook (JC) model. The physical mechanisms responsible for this behaviour are also studied. The model is developed by experimental quasi-static and high strain rate axisymmetric compression testing from 20°C to 720°C and implemented into 3D finite element drilling simulations. The improvement over the original JC model is demonstrated by comparison to experimentally measured torque and thrust force.